Constant field gradient planar coupled cavity structure

Abstract

A cavity structure having at least two opposing planar housing members spaced apart to accommodate the passage of a particle beam through the structure between the members. Each of the housing members have a plurality of serially aligned hollows defined therein, and also passages, formed in the members, which interconnect serially adjacent hollows to provide communication between the hollows. The opposing planar housing members are spaced and aligned such that the hollows in one member cooperate with corresponding hollows in the other member to form a plurality of resonant cavities aligned along the particle beam within the cavity structure. To facilitate the obtaining of a constant field gradient within the cavity structure, the passages are configured so as to be incrementally narrower in the direction of travel of the particle beam. In addition, the spacing distance between the opposing housing members is configured to be incrementally smaller in the direction of travel of the beam.

We claim: 
     
       1. A cavity structure including at least two opposing housing members spaced apart to accommodate the passage of a particle beam, having a direction of travel, through the structure, between the members, each of said housing members having a plurality of serially aligned hollows defined therein, said respective hollows configured to define partition walls between each adjacent hollow and said partition walls including respective passages with a defined width, provided in the corresponding partition walls and interconnecting said serially adjacent hollows to provide communication between the hollows, such that said serially aligned hollows in one of said member cooperates with the corresponding hollows in the other one of said housing member to provide a plurality of resonant cavities aligned along the direction of travel of the particle beam within the cavity structure, and wherein the respective passages are configured to be incrementally smaller in width along the direction of travel of the particle beam. 
     
     
       2. The cavity structure of claim 1 and further including cooling channels defined within the housing members. 
     
     
       3. The cavity structure of claim 1 wherein the opposing housing members are spaced in such manner as to provide a distance between the housing members which is incrementally smaller in the direction of travel of the particle beam. 
     
     
       4. The cavity structure of claim 1 wherein said plurality of hollows are generally oval in shape. 
     
     
       5. The cavity structure of claim 1 wherein said respective passages have rounded corners. 
     
     
       6. The cavity structure of claim 1 and means for spacing and aligning said opposing housing members positioned within the cavity structure and between the housing members, said means for spacing and aligning said opposing housing members being configured so as to accommodate the passage of the particle beam between the members and allow the respective hollows to cooperatively provide said plurality of resonant cavities aligned along the particle beam. 
     
     
       7. The cavity structure of claim 6, wherein said means for spacing and aligning includes glass fiber spacers positioned within respective longitudinal grooves defined within said opposing housing members. 
     
     
       8. The cavity structure of claim 6, wherein said means for spacing and aligning said opposing housing members includes DXL generated pegs on the respective housing members which connect, space and align opposing housing members. 
     
     
       9. The cavity structure of claim 1 and means for injecting rf power connected to said cavity structure. 
     
     
       10. The cavity structure of claim 9 wherein said means for injecting rf power is connected to respective hollows and includes waveguide couplers defined within the corresponding housing members. 
     
     
       11. The cavity structure of claim 10 wherein said waveguide couplers are selected from a group consisting of inductive iris coupling; capacitive iris coupling; inductive post coupling; and series stub coupling. 
     
     
       12. A cavity structure for accommodating the passage of a particle beam, having a direction of travel, through the structure, said cavity structure being configured to provide a plurality of resonant cavities aligned along the direction of travel of the particle beam, said resonant cavities having openings which interconnect serially adjacent cavities to provide cavity-to-cavity coupling, and said respective openings configured to be incrementally smaller in the direction of travel of the beam. 
     
     
       13. The cavity structure of claim 12, wherein said openings are configured so as to facilitate the attainment of a constant field gradient within the cavity structure. 
     
     
       14. A cavity structure including at least two opposing housing members spaced apart to accommodate the passage of a particle beam, having a direction of travel, through the structure and between the members, each of said housing members having a plurality of serially aligned hollows defined therein, with said respective hollows configured to define partition walls between each adjacent hollow and said partition walls including respective passages provided in the corresponding partition walls and interconnecting said serially adjacent hollows to provide communication between the hollows, such that said serially aligned hollows in one of said member cooperates with the corresponding hollows in the other one of said housing member to provide a plurality of resonant cavities aligned along the particle beam direction within the cavity structure, and wherein said hollows, partition walls, and passages provided in said corresponding housing members are manufactured using x-ray lithographic processes. 
     
     
       15. The cavity structure of claim 14 wherein the respective passages are configured to be incrementally smaller in the direction of travel of the particle beam.